Machine for grinding glass



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J. W. BONTA. MAGHINB FOR GRINDING GLASS.

` No. 483,527. Pmnted om.. 4.1892.

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3 Sheets-Sheet 2.

(No Model.)

J. W. BONTA. MACHINE -PoR GRINDING GLASS;

Patented Oct. 41892.

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(No Model.) `3 Sheets- Sheet 3.

J. W. BONTA. MACHINE POB. GRINDING GLASS.

No. 483,527. Patented Ont. 4, 1892.

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UNITED STATES PATENT OFFICE.-

JAMES W. BONTA, OF WAYNE, ASSIGNOR TO JAMES H. SHAKESPEARE, l

TRUSTEE, OF PHILADELPHIA, PENNSYLVANIA.

MACHINE FOR GRINDING GLASS.

SPECIFICATION forming part of Letters Patent No. 483,527, dated October 4, 1892. Application iiled August 27, 1891:. Serial No. 403,846. (No model.)

To all whom it may concern:

Be it known that I, J AMES W. BoNTA, a citizen of the United States, and a resident of Wayne, Delaware county, Pennsylvania, have invented certain Improvements in Machines for Grinding Glass, of which the following is a specication.

The object of my invention is to provide means for reversing plate and sheet glass in a grinding-machine, so as to grind both surfaces of the glass, as fully described hereinafter.

In the accompanying drawings, Figure I is a side view showing the grinding-bed of a grinding-machine with the mechanism for reversing the plate of glass, the grinding mechanism being omitted to avoid complication. Fig. 2 is a side view similar to that shown in Fig. l, but showing the plate clamped between the two platens ready to be lifted and reversed. Fig. 3 is a sectional plan on the line 1 2, Fig. l. Fig. Lt is a sectional plan on the line 3 4t, Fig. I; and Fig. 5 is a transverse sectional view showing the glass clamped between the two platens and in the act of being reversed.

I-Ieretofore in the manufacture of glass, especially plate-glass, the glass is usually in very large sheets, and when placed on the bed or platen of the grinding-machine has to be handled very carefully in order to prevent it from cracking or breaking, and when turned so as to expose the opposite face after one face is ground it has to be handled with the greatest care by a number of men to prevent it from sagging and breaking, and a great' percentage of the glass broken is broken during the grinding and during the adjusting of the plate to the grinding platen or' bed. Therefore the main object of my invention is to handle the glass in a perfectly-safe manner and to dispense with the extra help heretofore needed, as by my invention one man can readily manipulate the glass.

Referring to the drawings, A is the base of the machine having a central shaft c, provided with a pocket a', to receive the post b of the platen B, upon which the glass a: rests. The platenisin the present instance also supported by antifriction-rollers c, arranged in suitable bearings on the base of the machine. The

shaft a has a bevel gear-wheel a2, meshing with the bevel-wheel as on a shaft a4, mounted in bearings in the base of the machine and provided with a belt-pulley. This shaft is the driving-shaft for turning the platen under the grinders, which are omitted to avoid confusion, as any suitable grinders may be used without departing from my invention.

D D are two standards connected together at their upper ends by the cross-barD. These standards are slotted, and adapted to slide in these slots are frames E E, carrying the pivots e e, upon which the platens are turned, as fully described hereinafter.

At each side of the platen B are bearings hb for the pivot-pins@ c, and resting upon the pins, as shown in Fig. 1, is a second platen B', having bearings b2, and a post b similar to the post of the platen B.

The sliding frames E E are raised and lowered by mechanism which I will describe hereinafter. t

On one of the pivot-pin carriers is a turning-wheel G, by which the two platens are turned to reverse the plate of glass. The wheel has in the present instance two pins which pass between the platens, so that any rotary motion given to the wheel will be imparted to the platens.

Before describing the mechanism by which the pivots are raised and lowered I will describe tlie Operation of as much of the machine as I have noted above, as it will be understood that any suitable mechanism may be used for raising and lowering the platens.

The glass m is placed on the lower platen B in any suitable manner. The platen being removable, it can be detached from the grinding-machine, if necessary, and receive the glass at the most convenient point, and then be placed upon the machine. Afterone side of the glass has been ground the slides carrying the pivot-pin, on which is mount-ed the platen B', are lowered from the position shown in Fig. l to the position shown in Fig. 2, and when the second platen B rests upon the glass the two platens B B are secured together in any suitable manner. In the present instance I have shown hooks c; but it may be necessary to use clamping bolts, which will accommodate the different thick- IOO nesses of the glass. Af ter the two platens are secured together, with the glass between them, they are raised tothe position shown by dotted lines in Fig. 2 and then turned by the hand-wheel G, as shown in Fig. 5, so as to reverse the sheet of glass and the platens, the platen B becoming the under platen. two platens are then lowered to the position shown by full lines in Fig. 2 and uncoupled. The slides E are then raised to the position shown in Fig. I, exposing the unground snrface of the glass to the grinders. Thus the sheet of glass is reversed without the liability of' its being broken, the whole operation being done very quickly and bythe single-attendant who has charge of the grinding-machine.

In place of the hand-wheel shown I may tur'n the platens from one of the power-driven shafts of the machine through intervening gearing and clutching mechanism.

I will now describe the mechanism by which the platens are raised and lowered. Adapted to each slide E is a vertical screw-rod h, having at its upper end a bevel-wh eei h', meshing with a bevel-Wheel h2 on the shaft H. This shaft is provided with a belt-p ulley and is driven from any power-shaft, so that on turning` the shaft H the slides E E will be raised or lowered, according to the direction in which the shaft H is turned.

The shaft H is mounted in suitable bearings on the cross-bar D", and the screw-rods are also adapted to bearings in said cross-rod.

In order t0 securely lock the two platens B YBto vthe,pivot-pins, I.Y provide7 laterally-ade justable sleeves n, (shown clearly in Fig. 3,) which can be forced out over the bearing b b2, as clearly shown in Fig. 2, thus forming a lock in addition to the hooks. These sleeves are forced Vout by mechanism which I will now describe.

On the slides E E are two vertical shafts N N, one on each slide. On the lower end ot' each shaft is a cam n', adapted to a cam-plate n2, which extends through and is guided by the bearing N This cam-plate n2 snugly fits the sleeveN, so that any transverse motion given to the cam-.plate by the cam Will move the sleeve in or out, as shown by dotted lines in Fig. 3. At the upper end of each shaft is a gear-wheel t', meshing with the teeth p p of a rack-bar P. This rack-bar is moved by a lever T, pivoted to the rack-bar at q and to a link u, which in turn is pivoted to one of the The slides E, so that by moving the lever T from the position shown in Fig. l to the position shown in Fig. 2'the cams are turned and the sleeves forced out over the bearings of the two platens, iirmly locking the platens together.

I claim as my invention- 1. The combination, in a grinding-machine, of the mechanism for rotating the glass under the grinders, a platen adapted to said mechanism and on which the glass to be ground is mounted, a second platen, also adapted to the rotating mechanism, means for securing the two platens together, and means for reversing the platens with the glass between them, substantially as described.

V2. The combination of the two platens adapted t'o clamp the glass between them, mechanism for rotating the platen carrying the glass beneath the grinders, bearings on each of said platens, pivots adapted to said bearings, and vertically-adj ustable frames carrying said pivots, substantially as described.

3. The combination of the two platens, mechanism for rotating the lower platen when in position, bearings on each of said platens, vertically-movable slides carrying pivot-pins adapted to the bearings, sleeves extending over said bearings, and mechanism for advancing and withdrawing said sleeves, substantially as described.

4. The combination of the two platens, the slides E E, pivot-pins on said slides, to which the pla-tens are adapted, vertical screw-rods adapted to said slides, and a driving-shaft geared to bot-h of said screw-rods, substantially as described. Y. Y

5. The combination'ofthre two platens, two Y u Y Y u slides, pivot-pins on said slides, adapted to bearings on the platens, mechanism for raising and lowering the said slides, sleeves on each slide capable of being moved over the bearings of the platens, vertical cam-shafts carried by the slides, cams on said shafts, adapted to move the sleeves, pinions on said shafts, with a rack-bar engaging said pinions, and mechanism for moving said rack-bal', substantially as described.

In testimony Whereoi` I have signed my name to this specication in the presence of two subscribing witnesses.

JAMES W. B'ONTA.

Witnesses:

WILLIAM M. STEWART, J r., HENRY HovvsoN.

IOO 

